It might be good to get him tested since respiratory diseases can be viral, mycoplasmal, or bacterial. The viral diseases won't respond to antibiotics, but the AB's can help to prevent secondary diseases. Secondary diseases such as air sacculitis, can complicate any disease. What symptoms besides sneezing are you seeing? Tylan 50 injectable is a bit stronger, and it can be given orally as well as by injection. If it is a virus, it will have to run it's course. Many respiratory diseases make carriers of your flock for life, so knowing what it is helps.
Edited by Eggcessive - 11/14/15 at 4:21pm